U.S. patent application number 10/565734 was filed with the patent office on 2007-03-29 for cannula/catheter introducer.
Invention is credited to Aaron Rodd.
Application Number | 20070073237 10/565734 |
Document ID | / |
Family ID | 32476281 |
Filed Date | 2007-03-29 |
United States Patent
Application |
20070073237 |
Kind Code |
A1 |
Rodd; Aaron |
March 29, 2007 |
Cannula/catheter introducer
Abstract
A device is disclosed that allows a puncture needle to be
inserted into a catheter. Once the puncture needle has performed
its function, it can shoot back into the device such that there is
a reduce likelihood of needlestick injury. Vacuum is used to assist
in the shoot back function.
Inventors: |
Rodd; Aaron; (Queensland,
AU) |
Correspondence
Address: |
ANTONELLI, TERRY, STOUT & KRAUS, LLP
1300 NORTH SEVENTEENTH STREET
SUITE 1800
ARLINGTON
VA
22209-3873
US
|
Family ID: |
32476281 |
Appl. No.: |
10/565734 |
Filed: |
July 30, 2004 |
PCT Filed: |
July 30, 2004 |
PCT NO: |
PCT/AU04/01012 |
371 Date: |
January 24, 2006 |
Current U.S.
Class: |
604/164.01 |
Current CPC
Class: |
A61M 25/0637 20130101;
A61B 5/150389 20130101; A61B 5/150221 20130101; A61M 2005/3235
20130101; A61B 5/150519 20130101; A61B 5/1535 20130101; A61M
25/0631 20130101; A61B 5/150656 20130101; A61M 2005/3242 20130101;
A61B 5/150259 20130101; A61B 5/15003 20130101 |
Class at
Publication: |
604/164.01 |
International
Class: |
A61M 5/178 20060101
A61M005/178 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 31, 2003 |
AU |
2003903990 |
Claims
1. A cannula/catheter introducer comprising an outer tubular member
which has a proximal end and a distal end, an inner tubular member
adapted for sliding movement within the outer tubular member, the
inner tubular member having an open proximal end, and a closed
distal end, an end member which closes the open proximal end of the
inner tubular member, a sealing means on the end member to
sealingly engage with the inner tubular member, release means on
the end member and which is movable between a first position where
the release means locks the end member to the inner tubular member,
and a second position where the release means is unlocked from the
inner tubular member and allows the end member to retract through
the inner tubular member, the inner tubular member being under
vacuum, the vacuum functioning to retract the end member from the
proximal end of the inner tubular member towards the distal end of
the inner tubular member, the release means being movable from the
first position to the second position when the inner tubular member
is at or adjacent the proximal end of the outer tubular member, a
needle holder which is attached to the proximal end of the outer
tubular member, release means on the needle holder and which is
moveable between a first position where the release means locks the
needle holder to the outer tubular member, and a second position
where the release means is unlocked from the inner tubular member,
wherein, when the inner tubular member is at or adjacent the
proximal end of the outer tubular member, the release means on the
end member unlocks from the inner tubular member, and locks against
the release means on the needle holder, and causes the release
means on the needle holder to move to the unlocked position, after
which the end member and the needle holder is retracted into the
inner tubular member by virtue of the vacuum in the inner tubular
member.
2. The introducer as claimed in claim 1 wherein the inner tubular
member is movable between a retracted position and an extended
position, and when in the retracted position, the tubular member is
spaced from the needle holder by a short distance, and when in the
extended position, the tubular member triggers retraction of the
needle holder, the inner tubular member being held captive within
the outer tubular member in the retracted position.
3. The introducer as claimed in claim 2 wherein the distal end of
the outer tubular member and the distal end of the inner tubular
member comprise captive means, the captive means comprising a
longitudinal passageway in the outer tubular member and a
projection extending from the inner tubular member, the projection
adapted for movement along the longitudinal passageway to design
the travelling limit of the inner tubular member within the outer
tubular member.
4. The introducer as claimed in claim 2 wherein the proximal end of
the outer tubular portion is restricted in diameter with respect to
the remainder of the outer tubular portion and contains a number of
stepped portions to progressively reduce the diameter of the
proximal end while still providing internal land portions.
5. The introducer as claimed in claim 2 containing gripping means
or locking means on an inner wall at the proximal end of the outer
tubular member which function to assist in locking the needle
holder to the proximal end of the outer tubular member.
6. The introducer as claimed in claim 5 wherein the gripping means
or locking means comprises an internal annular groove in the
proximal end of the outer tubular member.
7. The introducer as claimed in claim 2 wherein the end member
comprises a rear portion and a front portion, the rear portion
being substantially closed and containing the sealing means to
enable the end member to be sealing engaged to the inner wall of
the inner tubular member in a sliding but sealing manner.
8. The introducer as claimed in claim 7 wherein the front portion
contains the release means.
9. The introducer as claimed in claim 8 wherein the release means
comprises at least one finger member which is resilient and which
is adapted for movement between a natural first position and a
deformed second position.
10. The introducer as claimed in claim 9 wherein the at least one
finger member, when in the first position, locks against the open
proximal wall of the inner tubular member.
11. The introducer as claimed in claim 10 wherein the at least one
finger member is provided with an arrowhead configuration to enable
the finger member to lock against the open proximal wall of the
inner tubular member.
12. The introducer as claimed in claim 1 wherein the needle holder
has a central body portion which contains a passageway to
accommodate a puncture needle, the release means being formed
integrally with the central body portion.
13. The introducer as claimed in claim 12 wherein the release means
comprises at least one finger member, the finger member comprising
a configuration to enable the finger member to engage with the
release means on the end member.
14. The introducer as claimed in claim 13 wherein the finger member
contains an intermediate projection that engages with a recess in
the outer tubular member to releasably lock the needle holder to
the outer tubular member.
15. A cannula/catheter inserter, the inserter comprising an outer
tubular member which has a proximal end and a distal end, an inner
tubular member adapted for sliding movement within the outer
tubular member, the inner tubular member having an open proximal
end and a closed distal end, a needle holding piston assembly which
closes the open proximal end of the inner tubular member, a sealing
means on the needle holding piston assembly to sealingly engage
with the inner tubular member, release means on the needle holding
piston assembly and which is movable between a first position where
the release means locks the needle holding piston assembly to the
inner tubular member, and a second position where the release means
is unlocked from the inner tubular member and allows the needle
holding piston assembly to retract through the inner tubular
member, the inner tubular member being under vacuum, the vacuum
functioning to retract the needle holding piston assembly from the
proximal end of the inner tubular member towards the distal end of
the inner tubular member, the release means being movable from the
first position to the second position upon movement of the inner
tubular member towards the proximal end of the outer tubular
member, wherein, upon movement of the inner tubular member towards
the proximal end of the outer tubular member, the release means on
the needle holding piston assembly unlocks from the inner tubular
member, after which the needle holding piston assembly is retracted
into the inner tubular member by virtue of the vacuum in the inner
tubular member.
16. The inserter as claimed in claim 15 wherein the inner tubular
member is movable between a retracted position and an extended
position, and when in the retracted position, the tubular member is
spaced from the needle holding piston assembly by a short distance,
and when in the extended position, the tubular member triggers
retraction of the needle holding piston assembly, the inner tubular
member being held captive within the outer tubular member such that
the inner tubular member can only move by the short distance.
17. A cannula/catheter introducer, the introducer comprising an
outer tubular member, an inner tubular member, needle retraction
means to enable the puncture needle to be retracted into the inner
tubular member upon forward movement of the inner tubular member
relative to the outer tubular member, the inner tubular member
being substantially inserted into the outer tubular member such
that the proximal end of the inner tubular member is adjacent the
proximal end of the outer tubular member, the introducer comprising
limit means to limit the travel of the inner tubular member
relative to the outer tubular member, the limit means being
adjacent a distal end of the introducer.
18. The introducer as claimed in claim 1, wherein the release means
moves from the first position to the second position by movement of
the upper tubular member towards the proximal end of the outer
tubular member.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to cannula or catheter
introducer devices and has particular relevance to such devices
with retractable needles.
BACKGROUND ART
[0002] Catheter insertion devices are well known in the art. When a
catheter is inserted into a patient for the intravenous delivery of
a fluid, a disposable needle passing through the catheter cannula
is utilized to make a puncture to permit entry of the tip of the
cannula into the patient. The needle is then withdrawn leaving the
catheter in place either for a direct hook-up to a bottle of fluid
to be delivered, or to be capped for later use. The needle which is
now contaminated with blood or other body fluid must be disposed of
without creating a risk of needle sticks to medical personnel which
are engaged in the operation of inserting a catheter. A danger to
clean up and medical waste disposal personnel continues if the used
needles are not rendered harmless in some way. Caps or covers that
can be mounted over the needle are not a satisfactory solution
because they must be put in place and can become loose and expose
the used needle.
[0003] A discussion of the problems associated with various
approaches and uses of cannula insertion products is found in
Kulli, U.S. Pat. No. 4,747,831.
[0004] Retractable needles have been recognized as the best
solution to these problems.
[0005] A number of these approaches are disclosed in U.S. Pat. No.
4,747,831 mentioned above which includes an external latch
mechanism which is pushed to release a spring loaded needle which
is withdrawn into the chamber of the device. Some embodiments have
a sliding block and retractable fingers which depress springloaded
ears to allow retraction of the needle holder, racheting devices
which unlatch the needle holder by rotation of parts and even
frangible parts which are broken when a plunger is pushed
forward.
[0006] Dysarz, U.S. Pat. No. 5,129,884, is another example of an
external latch which may be disengaged to allow a needle holder to
withdraw a needle into the main body of the device. Walter, U.S.
Pat. No. 4,828,548, discloses a holder having a piston which may be
operated on by vacuum to withdraw a needle. Erskine, U.S. Pat. No.
5,501,675, is a more recent version of a latch-operated device
wherein a needle holding part may be released with an external
latch.
[0007] The devices of the prior art have complicated parts which
are difficult to manufacture and especially difficult to assemble
in a high speed manufacturing operation. Many of them are prone to
premature firing during handling and with some, it is difficult to
know when the needle is safe. Disengagement of the catheter
assembly from the retraction device is not fully under the timing
and control of the medical operator because retraction results in
immediate separation of the device form the cannula assembly.
[0008] It is an object of the present invention to provide a
simplified cannula/catheter introducer which is safe to use and can
be produced at a modest cost and which uses a vacuum to retract a
contaminated needle to reduce needle stick injury.
[0009] Further objects and advantages of the present invention will
become apparent from the ensuing description which is given by way
of example only.
DISCLOSURE OF INVENTION
[0010] In one form, the invention resides in a cannula/catheter
introducer comprising an outer tubular member which has a proximal
end and a distal end, [0011] an inner tubular member adapted for
sliding movement within the outer tubular member, the inner tubular
member having an open proximal end, and a closed distal end, [0012]
an end member which closes the open proximal end of the inner
tubular member, [0013] a sealing means on the end member to
sealingly engage with the inner tubular member, [0014] release
means on the end member and which is movable between a first
position where the release means locks the end member to the inner
tubular member, and a second position where the release means is
unlocked from the inner tubular member and allows the end member to
retract through the inner tubular member, the inner tubular member
being under vacuum, the vacuum functioning to retract the end
member from the proximal end of the inner tubular member towards
the distal end of the inner tubular member, the release means being
movable from the first position to the second position upon
movement of the inner tubular member towards the proximal end of
the outer tubular member, [0015] a needle holder which is attached
to the proximal end of the outer tubular member, release means on
the needle holder and which is moveable between a first position
where the release means locks the needle holder to the outer
tubular member, and a second position where the release means is
unlocked from the inner tubular member, [0016] wherein, upon
movement of the inner tubular member towards the proximal end of
the outer tubular member, the release means on the end member
unlocks from the inner tubular member, and locks against the
release means on the needle holder, and causes the release means on
the needle holder to move to the unlocked position, after which the
end member and the needle holder is retracted into the inner
tubular member by virtue of the vacuum in the inner tubular
member.
[0017] In another form, the invention resides in a cannula/catheter
introducer comprising an outer tubular member which has a proximal
end and a distal end, [0018] an inner tubular member adapted for
sliding movement within the outer tubular member, the inner tubular
member having an open proximal end and a closed distal end, [0019]
an end member which closes the open proximal end of the inner
tubular member, [0020] a sealing means on the end member to
sealingly engage with the inner tubular member, [0021] release
means on the end member and which is movable between a first
position where the release means locks the end member to the inner
tubular member, and a second position where the release means is
unlocked from the inner tubular member and allows the end member to
retract through the inner tubular member, the inner tubular member
being under vacuum, the vacuum functioning to retract the end
member from the proximal end of the inner tubular member towards
the distal end of the inner tubular member, the release means being
movable from the first position to the second position upon
movement of the inner tubular member towards the proximal end of
the outer tubular member, [0022] a needle holder which is attached
to the proximal end of the outer tubular member, release means on
the needle holder and which is moveable between a first position
where the release means locks the needle holder to the outer
tubular member, and a second position where the release means is
unlocked from the inner tubular member, [0023] the inner tubular
member being movable between a retracted position and an extended
position, and when in the retracted position, the tubular member is
spaced from the needle holder by a short distance, and when in the
extended position, the tubular member triggers retraction of the
needle holder, the inner tubular member being held captive within
the outer tubular member in the retracted position, [0024] wherein
upon movement of the inner tubular member towards the proximal end
of the outer tubular member, the release means on the end member
unlocks from the inner tubular member, and locks against the
release means on the needle holder and causes the release means on
the needle holder to move to the unlocked position, after which the
end member and the needle holder is retracted into the inner
tubular member by virtue of the vacuum in the inner tubular
member.
[0025] In this form of the invention, because the device functions
to insert a puncture needle into a catheter or cannula, the device
does not function as a syringe. Therefore, the inner tubular member
in the initial position is substantially entirely within the outer
tubular member and is only a short distance away from the needle
holder. For instance, it is envisaged that the inner tubular member
can be spaced between 1-20 millimetres from the needle holder, and
preferably between 3-10 millimetres. As it is not desirable for the
inner tubular member to be retracted too far in the outer tubular
member (as the device does not function as a syringe), some form of
locking arrangement can be provided to ensure that the inner
tubular member can move only by a short distance between the
retracted position and the forward (triggering) position.
[0026] The introducer can be of any suitable shape and size which
will depend, inter alia, on the size of the cannula or catheter. It
is envisaged that the introducer will be made of suitable material
such as plastic although some components (e.g. the sealing means)
may be made of rubber or composite materials. However, no
particular limitation is to be placed on the invention merely by
the material from which the device is manufactured. The size of the
introducer can vary, and it is envisaged that the length will be
between 50-300 millimetres and typically between 100-200
millimetres. Again, no particular limitation should be placed on
the invention merely by the size of the device. The introducer may
have a diameter of between 5-50 millimetres and typically between
10-20 millimetres although no particular limitation should be
placed on the invention merely by the diameter of the
introducer.
[0027] The outer tubular member may comprise finger grippable
portions to assist in a one-handed operation in depressing the
inner tubular member within the outer tubular member. The finger
grippable portions may comprise extending members adjacent the
proximal end of the outer tubular member and dimensioned to enable
fingers to grip these portions.
[0028] The proximal end of the outer tubular portion may be
restricted in diameter with respect to the remainder of the outer
tubular portion. Suitably, the proximal end contains a number of
stepped portions to progressively reduce the diameter of the
proximal end while still providing internal land portions.
[0029] The end of the proximal end of the outer tubular portion may
comprise a nozzle adapted for insertion into the rear of a
catheter.
[0030] Gripping means or locking means may be provided on an inner
face at the proximal end of the outer tubular member to assist in
gripping or locking the needle holder. The gripping means or
locking means may comprise a recess such as an annular groove.
[0031] The distal end of the outer tubular member may be provided
with a locking means to restrict movement of the inner tubular
member relative to the outer tubular member. Suitably, the locking
means comprises an enlargement on the outer tubular member and
adjacent the distal end, the enlargement defining a small
travelling passageway which defines the limits of movement of the
inner tubular member relative to the outer tubular member. The
passageway may have a length of between 3-20 millimetres and
typically between 3-10 millimetres. The passageway may contain
engagement means to "lightly" engage with the inner tubular member.
The engagement means may comprise a pair of spaced apart small
ribs, which may be annular in configuration. The function of the
engagement means may be to lightly hold the inner tubular member in
the retracted position such that the inner tubular member does not
inadvertently move to the extended position thereby triggering the
shoot-back mechanism prematurely. However, the engagement means
should be such that a person can press on the back of the inner
tubular member to overcome the engagement means when desired.
[0032] The inner tubular member, in use, will have reduced
pressure, or be under vacuum. The inner tubular member will
typically have a closed distal end and an open proximal end, with
the open proximal end being closed by the end member. Typically,
the inner tubular member will comprise a hollow tube with an open
front end. The distal end of the inner tubular member will
typically be provided with locking means to lock against the distal
end of the outer tubular member in such a manner that the degree of
sliding movement of the inner tubular member within the outer
tubular member is predetermined. The locking means may comprise a
projection which may be an annular rib that sits within the
passageway that may be provided on the distal end of the outer
tubular member.
[0033] The end member closes the otherwise open proximal end of the
inner tubular member. The end member may comprise a rear portion
and a front portion. The rear portion may be substantially closed
and may be provided with the sealing means to enable the end member
to be sealingly engaged to the inner wall of the inner tubular
member in a sliding but sealing manner. The sealing means may
comprise a sealing ring that is fitted about the rear portion and
which comprises at least one, and preferably a plurality of,
spaced-apart ring members that sealingly engage against the inside
wall of the inner tubular member.
[0034] The front portion may contain or comprise the release means.
The release means may be formed integrally with the rear portion.
The release means may comprise at least one finger member. The
finger member may be resiliently formed to move between a natural
first position and a deformed second position. Suitably, the finger
member deforms inwardly between the first position and the second
position. Suitably, a plurality of finger members is provided and
these may be spaced equally about the end member. The or each
finger member may extend forwardly from the end member and towards
the needle holder.
[0035] The end member may have a length of between 5-20 millimetres
although this can vary to suit.
[0036] A "flash" chamber may be provided in the end member to
enable the first flash of blood or body fluid to be viewed as the
puncture needle penetrates into a patient's vein, etc.
[0037] The or each finger member in the natural first position may
lock against the inner tubular member and preferably lock against
the open proximal wall of the inner tubular member. It is preferred
that the or each finger member is profiled to facilitate this type
of locking. Therefore, it is preferred that the or each finger
member contains a step, or a shoulder, or have an arrowhead-type
configuration to enable the or each finger member to abut against
or lock against the open proximal wall of the inner tubular
member.
[0038] The needle holder is attached to the proximal end of the
outer tubular member and is preferably positioned in the stepped or
narrowing position of the outer tubular member. The needle holder
may be made of any suitable material such as plastic, rubber,
composite materials and the like. The needle holder will typically
comprise a central body portion. The central body portion may
contain a small passageway through which a puncture needle can be
fitted to fit the puncture needle to the needle holder. The release
means may be formed integrally with the remainder of the needle
holder. The release means may comprise at least one finger member.
The at least one finger member may be movable or deformable between
a natural position which is the first position and a deformed
position which is the second unlocking position. The at least one
finger member may be cantilevered from the central body portion and
may extend towards the inner tubular member. Suitably, a plurality
of finger members is provided and these may be spaced equally about
the central body portion. Each finger member may be provided with a
terminal configuration which may comprise a shoulder, a step
portion, a hook portion, or an arrowhead portion, the function of
which is to facilitate engagement with the finger member on the end
member as will be described in greater detail below. Also, each
finger member may comprise an intermediate projection such as an
annular ring which engages into the recess on the outer tubular
member to temporarily lock the needle holder to the outer tubular
member.
[0039] In another form, the invention resides in a cannula/catheter
inserter, the inserter comprising [0040] an outer tubular member
which has a proximal end and a distal end, [0041] an inner tubular
member adapted for sliding movement within the outer tubular
member, the inner tubular member having an open proximal end, and a
closed distal end, [0042] a needle holding piston assembly which
closes the open proximal end of the inner tubular member, [0043] a
sealing means on the needle holding piston assembly to sealingly
engage with the inner tubular member, [0044] release means on the
needle holding piston assembly and which is movable between a first
position where the release means locks the needle holding piston
assembly to the inner tubular member and a second position where
the release means is unlocked from the inner tubular member and
allows the needle holding piston assembly to retract through the
inner tubular member, the inner tubular member being under vacuum,
the vacuum functioning to retract the needle holding piston
assembly from the proximal end of the inner tubular member towards
the distal end of the inner tubular member, the release means being
movable from the first position to the second position upon
movement of the inner tubular member towards the proximal end of
the outer tubular member, [0045] wherein upon movement of the inner
tubular member towards the proximal end of the outer tubular
member, the release means on the needle holding piston assembly
unlocks from the inner tubular member, after which the needle
holding piston assembly is retracted into the inner tubular member
by virtue of the vacuum in the inner tubular member.
[0046] It is preferred that the inner tubular member is movable
between a retracted position and an extended position and when in
the retracted position, the tubular member is spaced from the
needle holding piston assembly by a short distance and when in the
extended position, the tubular member triggers retraction of the
needle holding piston assembly, the inner tubular member being held
captive within the outer tubular member such that the inner tubular
member can only move by the short distance.
[0047] The short distance may be as described above and will of
course depend on the size of the device. However, it is the
intention that the inner tubular member can move forward by only a
short distance to trigger the shoot back mechanism. Typically, this
distance will be between 1-20 millimetres and preferably between
3-10 millimetres.
[0048] Suitably, the inner tubular member and the outer tubular
member are substantially as described above with reference to the
first embodiment of the invention.
[0049] The needle holding piston assembly may have a length of
between 5-30 millimetres although no particular limitation should
be placed on the invention merely by this length. The piston
assembly may comprise a main body which has one closed end and one
open end and is substantially hollow. The closed end may be
provided with an enlargement onto which the sealing member can be
positioned. The sealing member may comprise any suitable type of
sealing member. The open end may contain a needle mounting block.
The needle mounting block typically contains a small passageway
through which the puncture needle can pass to fit the puncture
needle to the needle mounting block. A small flash chamber may be
provided in the main body. The needle mounting block will typically
contain the release means. The release means may comprise at least
one finger member. Suitably, a plurality of finger members is
provided. Each finger member may contain a terminal configuration,
which may comprise a step, a shoulder, a hook, or an arrowhead type
configuration to facilitate locking of the finger member and
therefore locking of the needle holding piston to the proximal end
of the inner tubular member.
[0050] In another form of the invention, there is provided a
cannula/catheter introducer comprising: [0051] (a) a cannula and
catheter connector assembly, [0052] (b) a retractable needle
assembly for assembly with the cannula and catheter assembly, and
[0053] (c) a valving member connected with the cannula and catheter
assembly for controlling in ingress and egress of fluids from a
patient.
[0054] The cannula and catheter connector assembly may be provided
with an inlet tube for releasable assembly with an outlet tube of a
retractable needle.
[0055] The valving member will typically be manually adjustable
from a first sealing position to a second flow position.
[0056] The valving member may comprise a plunger type valve.
[0057] Alternatively, the valving member may comprise a turn type
valve.
[0058] The retractable needle may be of the type described above,
and therefore may comprise an outer and inner casing, an outlet
from the casing, an internal piston within the inner casing
mounting a needle and a sealed compartment between the piston and a
closed end of the inner casing.
[0059] The sealed compartment contains partial pressure.
[0060] The outer casing is typically provided with wings for
gripping.
[0061] The piston may include a transparent vial section which
enables a user to establish that the needle has been correctly
inserted.
[0062] The vial may comprise a minute venting aperture.
[0063] With the present invention, the assembled catheter
introducer is handled as a unit. When the operator verifies that
the needle is properly inserted, one hand can hold the connector
that remains attached to the patient while the other hand separates
the retraction body which upon separation is automatically
retracted. A portion of the hand rests against the cannula to
prevent blood flow until the other hand inserts the conventional
tube into the catheter connector to start the infusion of fluid.
Immediately after separation, the retraction body safely contains
the retracted needle and the removed part is safely discarded.
BRIEF DESCRIPTION OF THE DRAWINGS
[0064] Embodiment of the invention will be described with reference
to the following illustrations.
[0065] FIG. 1 illustrates a section view of an introducer fitted to
a catheter and according to a second embodiment of the invention,
and in the "use" position.
[0066] FIG. 1a illustrates a close-up view of the proximal part of
the introducer and particularly illustrating the needle holding
piston.
[0067] FIG. 1b illustrates a close-up view of the distal part of
the introducer and particularly illustrates the mechanism that
limits travel of the inner tubular member in the outer tubular
member.
[0068] FIGS. 2 and 2a illustrate initiation of the "shoot back"
mechanism where the inner tubular member is being pushed forwardly
in the outer tubular member to deform the needle mounting
block.
[0069] FIGS. 3 and 3a illustrate the needle in the shoot back
position.
[0070] FIG. 4 illustrates the introducer removed from the catheter
with the puncture needle safely within the confines of the inner
tubular member.
[0071] FIGS. 5 and 6 illustrate section views of the catheter.
[0072] FIG. 7 illustrates a perspective view of the introducer
connected to the catheter.
[0073] FIG. 8 illustrates a section view of a first embodiment of
the invention with the introducer attached to a catheter and in the
"use" position.
[0074] FIG. 8a illustrates a close-up of the proximal end of the
introducer.
[0075] FIG. 8b illustrates a close-up of the distal end of the
introducer.
[0076] FIGS. 9 and 9a illustrate the introducer being moved to
trigger the shoot back mechanism.
[0077] FIGS. 9b and 10 illustrate the shoot back position where the
puncture needle is safely within the confines of the inner tubular
member.
[0078] FIG. 11 illustrates the introducer removed from the
catheter.
[0079] FIGS. 12-15 illustrate the valve on the catheter.
[0080] FIG. 16 illustrates a perspective view of the second
embodiment of the introducer attached to the catheter.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0081] Referring to FIGS. 8-16, there is illustrated a first
embodiment of the invention. Briefly, FIGS. 8-9a illustrate a
cannula/catheter introducer in the "use" position, while FIGS.
9a-11 illustrate the same introducer in the "shoot back" position.
FIGS. 12-15 illustrate the valve which forms part of the catheter
assembly and FIG. 16 is a perspective view of the device attached
to the catheter.
[0082] Referring initially to FIG. 16, there is illustrated a
catheter introducer 10 which comprises an outer tube 11. Outer tube
11 contains a pair of finger gripping wings 12. The front of outer
tube 11 contains a number of step portions 13 to ultimately finish
in an inlet 14.
[0083] A catheter assembly 15 can be attached to inlet 14 and
assembly 15 includes a valve 16 to enable the flow from the
catheter needle 17 to be regulated. FIGS. 12-15 illustrate
particularly valve 16. FIG. 12 is a section view showing the valve
in the "off" position and FIG. 13 is a plan view showing the valve
in the "off" position. FIGS. 14-15 illustrate similar views with
the valve in the "on" position. The valve can be moved manually
between the "on" position and the "off" position.
[0084] Referring now in greater detail to FIGS. 8, 8a and 8b, there
is illustrated details of the device 10. Briefly, the device
functions to enable a contaminated needle 18 to be "sucked" back
into the main body of the device after use thereby preventing
needle stick injury. Briefly, this is achieved by pushing the inner
tube 19 forwardly relative to outer tube 11 by distance of only a
few millimetres but this movement is sufficient to suck back a
contaminated needle. This will now be described in greater
detail.
[0085] Referring to FIGS. 8, 8a and 8b, there is illustrated the
device 10 attached to a catheter assembly 15. Device 10 has an
outer tube 11 and an inner tube 19 with the inner tube 19 able to
slide within outer tube 11 by a short distance (typically a few
millimetres). Outer tube 11 is cylindrical and can have a length of
between 10-20 centimetres and a diameter of between 5-20
millimetres although no particular limitation should be placed on
the invention merely by these dimensions. Outer tube 11 will
typically be made of suitable plastic material. Outer tube 11 has a
rear (distal) open end 20 to enable the inner tube 19 to be
manipulated. The open end 20 contains an enlarged collar 21 which
is best illustrated in FIG. 8b and which defines a small travelling
passageway 22 of a few millimetres.
[0086] Inner tube 19 is under vacuum and has a closed rear (distal)
end 23. This distal end is formed with an annular rib 24 which is
designed to move along passageway 22. The annular rib 24 enables
inner tube 19 to be moved forwardly (or be pressed into outer tube
11) which will cause the annular rib 24 to move from the rear
position illustrated in FIG. 8b to a forward position (not
illustrated) but where rib 24 has been moved to adjacent the
forward end of passageway 22.
[0087] Initially, device 10 is in the position illustrated in FIGS.
8, 8a and 8b. In this position, annular rib 24 is located within a
pair of spaced apart internal beads 25 (see FIG. 8b) to provide a
positive location of the inner tube 19 within the outer tube 11,
but which still enables a person to push the inner tube out of
engagement with the beads 25 when required.
[0088] Referring to FIG. 8a, the forward part of outer tube 11 as
mentioned above has a number of step portions 13 which terminate in
an inlet 14. Inlet 14 is designed to attach to the rear of the
catheter assembly 15 as is illustrated in FIG. 8.
[0089] The puncture needle 18 (see FIG. 8a) is secured to a needle
holder 26 of special design and which forms part of the shoot back
mechanism which enables needle 18 to be shot back into the rear of
inner tube 19 (see FIG. 10 and FIG. 11). Needle holder 26 is
initially attached to outer tube 11 but can be detached therefrom
as will be described in greater detail below. Needle holder 26
contains a plurality of resilient fingers 27. Each finger 27
contains an outwardly extending rib 28 that extends into a
corresponding recess on outer tube 11. This engagement locks needle
holder 26 to outer tube 19 and inside the stepped area 13. The
advantage of having a needle holder 26 initially locked to outer
tube 11 is that there is very little chance that any rearward force
on needle 18 will inadvertently release the needle holder
prematurely. Also, the needle will not move forwardly during the
triggering operation.
[0090] The resilient fingers 27 terminate in an arrowhead type
configuration 29 and initially this part of the resilient fingers
merely extends into the inside of outer tube 11 but is not attached
to anything.
[0091] The other part of the shoot back mechanism comprises an end
member 30. End member 30 is initially fitted to the open front
(proximal) end of inner tube 19 and is best illustrated in FIG. 8a.
End member 30 comprises a seal 31 which seals against the inside of
inner tube 19 to maintain vacuum inside the inner tube. End member
30 is however prevented against being sucked back into inner tube
19 by a plurality of resilient fingers 32. Fingers 32 are biased to
lock against the end of inner tube 19 (see FIG. 8a) and this
arrangement prevents end member 30 from being sucked back into
innertube 19.
[0092] The resilient fingers on end member 30 also have an
arrowhead type configuration, but the arrangement is such that
these resilient fingers are able to lock against the arrowhead
configuration 29 on resilient fingers 27 which form part of needle
holder 26. However, this does not occur until such time as inner
tube 19 is pushed forwardly.
[0093] In use, a catheter assembly 15 can be fitted to the end of
device 10 as illustrated in FIG. 8 and FIG. 16. The catheter can
then be inserted into a person's vein. The puncture needle 18
becomes contaminated during this procedure. Once the catheter
assembly 15 is in place, the conventional technique of removing the
puncture needle results in a needle stick risk. However, according
to the present invention, once the catheter assembly is in place, a
person can push inner tube 19 forwardly in a one-handed operation
by grasping the wings 12 with the person's fingers and using the
person's palm to push against end 23 of inner tube 19. This causes
rib 24 to push past the small locating beads 24 and along
passageway 22 (see FIG. 8b).
[0094] This forward movement (only a few millimetres) also causes
the forward end of inner tube 19 to move towards the stepped
portion 13 of outer tube 11 (this being best illustrated between
FIG. 8a and FIG. 9a). This forward movement causes the arrowhead
configuration on the end of fingers 32 to contact an internal
tapering face 34 (see FIG. 9a) which causes the fingers 32 to be
pushed inwardly. As this occurs, fingers 32 are released from the
inner edge of inner tube 19. As it is these fingers 32 that prevent
end member 30 from being sucked back, as soon as the fingers are
released, the end member will be sucked back into the distal
portion of inner tube 19.
[0095] Importantly, as fingers 32 are pushed inwardly and become
released from the edge of inner tube 19, they also engage behind
the arrowhead formation of fingers 27 which form part of needle
holder 26. Thus, as the fingers 32 are pushed inwardly, they lock
against fingers 27 and this means that the end member 30 becomes
locked to needle holder 26.
[0096] Therefore, as end member 30 is sucked back into the distal
end of inner tube 19, it also drags back needle holder 26 and
therefore the contaminated puncture needle 18, this position being
illustrated in FIG. 10 and FIG. 11.
[0097] The arrangement of having the needle holder 26 initially
attached to outer tube 11 means that the puncture needle 18
exhibits no forward movement by virtue of any of the shoot back
mechanism which forms part of the present invention.
[0098] FIGS. 12-15 illustrate the turn valve on the catheter. The
valve can turn manually between an open position and a closed
position as illustrated in the figures.
[0099] FIGS. 1-7 illustrate a second embodiment of the invention.
This embodiment also uses vacuum to suck back the contaminated
needle and is similar to the embodiment described with reference to
FIGS. 8-16. However, one difference is that instead of a two-part
needle holder/end member arrangement which is described in the
first embodiment, the second embodiment describes a single unit
which in the second embodiment is called a needle holding piston
assembly. One difference in the use of the second embodiment of the
invention is that triggering the shoot back mechanism does result
in the puncture needle moving forward by a few millimetres before
being shot back into the inner tube. Occasionally, this slight
forward movement can create discomfort to a patient.
[0100] The second embodiment (FIGS. 1-7) provides a
cannula/catheter introducer combination comprising a cannula and
catheter assembly generally indicated by arrow 41 (see FIG. 7) and
a retractable needle assembly generally indicated by arrow 42 for
connection to the cannula/catheter combination.
[0101] The cannula/catheter assembly 41 is provided with a valving
member generally indicated by arrow 43 for controlling the ingress
and egress of fluids from a patient.
[0102] The cannula/catheter assembly is provided with a body 44
having an inlet 45 (FIGS. 5 and 6) and an outlet 46 and the valving
member intersects with a valve body 47. The inlet 45 and outlet 46
respectively provide a needle aperture 48 and a slightly tapered
socket 49 for connection with an outlet nozzle 50 (see FIG. 1a) of
the needle assembly.
[0103] The valving member 43 includes a valve plunger 51 which is
adjustable from a first sealing position (FIG. 5) and a second flow
position (FIG. 6).
[0104] The plunger 51 has an aperture 52 therein supporting a
resilient pierceable gasket 53. The gasket 53 allows a puncture
needle 54 to pass through it and when the needle is withdrawn it
closes to seal off the needle penetration.
[0105] The plunger is also provided with a peripheral fluted
portion 55 which when positioned in the fluid mainstream 16 (see
FIG. 6) allows fluid to pass in both directions.
[0106] O-ring seals 57 ensure fluid tight sealing.
[0107] The retractable needle assembly 42 comprises outer and inner
tubes 58, 59 respectively (see FIG. 1) with the inner tube 59 being
a sliding fit in the outer tube 58.
[0108] The outer tube 58 comprises a bore and has an open rear
(distal) end 60 (see FIG. 1b) and is provided with forward finger
gripping wings 61. The front (proximal) end of the outer tube has a
nozzle 50 that inserts into the socket 49 on the
cannula/catheter.
[0109] The inner tube 59 has a closed rear (distal) end 62 (see
FIG. 1b) and an open front (proximal) end 63 (see FIG. 1a).
[0110] A needle holding piston assembly 64 (see FIG. 1a) is a
sliding fit within the inner tube 59. The piston assembly 64
comprises a hollow tubular body 65, which has an open front end and
a closed rear end. The closed rear end has a mounting knob 69. A
sealing member 68 is mounted over the knob 69. A needle mounting
block 66 is fitted to the open front end of the body 65.
[0111] The piston assembly 64 includes a transparent vial section
70, which enables medical staff to establish that the needle has
been correctly inserted when blood flows to the vial and is
visually detected.
[0112] The open distal end 60 of the outer tube 58 (FIG. 1b) is
provided with a shoulder 71 and the closed end 62 of the inner tube
59 has a complementary expanded portion 72 which ensures that the
inner tube is secured within the outer tube. Referring especially
to FIG. 1b, it can be seen that this arrangement allows the inner
tube to be pushed forwardly into the outer tube by a few
millimetres, this distance being defined by the length of the
recess 31a (which is a few millimetres). The arrangement also
ensures that the inner tube 59 cannot be readily pulled out of the
outer tube 58. This short stroke of a few millimetres is however
sufficient to trigger the shoot back mechanism of the needle as
will be described in greater detail below.
[0113] The front end of the needle mounting block 66 is provided
with a plurality of raked fingers 67. These fingers are formed
integrally with the needle mounting block and are resilient. The
fingers are designed to lock against the front of inner tube 59.
The function of fingers 67 is to prevent the needle holding piston
assembly 64 from moving along the inside of inner tube 59 from the
proximal end of the inner tube (see FIG. 1a) to the distal end of
inner tube (see, for instance, FIG. 3 and FIG. 4).
[0114] A vacuum is provided in inner tube 59 and seal 68 maintains
the vacuum inside inner tube 59. Thus, there is a force acting on
the needle holding piston assembly 64 to "suck" the needle holding
piston assembly 64 back into inner tube 59 towards the distal end
of the inner tube; however the resilient fingers 67 lock against
the front of inner tube 59 and prevent the needle holding piston
assembly 64 from being sucked back.
[0115] The arrangement described immediately above and illustrated
in FIG. 1 and FIG. 1a, is the initial position of the device.
[0116] To dislocate the fingers 67, the end 62 of the inner tube is
pushed forward using the palm of the hand whilst gripping the wings
61 with the fingers. The fingers are thereby forced into the
tapered section of the nozzle 50 and compressed to the extent that
the needle assembly is withdrawn under vacuum, the situation
illustrated by FIGS. 3 and 4.
[0117] More specifically, inner tube 59 can be pushed forwardly by
a few millimetres in the manner described immediately above which
moves the expanded portion 72 (see FIG. 1b) from the position
illustrated in FIG. 1b, to a position (not illustrated) where the
expanded portion is now at the other end of the recess 31a. This
short distance is sufficient to trigger the needle shoot back
mechanism. Specifically, and best illustrated in FIG. 2a, as the
inner tube 59 is pushed forwardly by a few millimetres, it will
push the needle holding piston assembly 64 forwardly by a few
millimetres. As this occurs, the resilient fingers 67 push
forwardly (as they form part of the needle block 66 which is
attached to the front of the needle holding piston assembly 64).
The front part of outer tube 58 tapers inwardly (see FIG. 1a) and
the resilient fingers 67 are arrow shaped in configuration which
means that as the resilient fingers are pushed forwardly, they will
be pressed inwardly (see FIG. 2a), and consequently they will
dislodge from the front of inner tube 59. As soon as the fingers 67
have been released from inner tube 59, the vacuum inside inner tube
59 will suck back the needle holding piston assembly 64 thereby
retracting the contaminated puncture needle 54 back into the body
of inner tube 59, this position being illustrated in FIG. 3 and
FIG. 4.
[0118] The forward movement of inner tube 59 is limited by the
arrangement illustrated in FIG. 1b, and also by a shoulder 73 (see
FIG. 2a) on outer tube 58.
[0119] Once the cannula/catheter device is secured and the needle
assembly removed, the cannula/catheter can be used for the
introduction or withdrawal of fluids to and from a patient.
[0120] The arrangement is simple to use and, in practice, once the
device has been inserted into the cannula assembly 41, the inner
tube 59 is pushed forwardly by just a few millimetres without any
requirement to rotate the inner tube or use any separate locking
mechanisms and upon forward pushing of the inner tube, the
contaminated needle 54 is sucked back to the rear of inner tube 59
to render the contaminated needle 54 safe. It is not possible to
push or otherwise enable the contaminated needle 54 to emerge from
the safety of inner tube 59. The arrangement is a simple one-handed
reliable arrangement.
[0121] FIGS. 1 and 2 of the drawings show the fully assembled
device as delivered for use, FIG. 3 of the drawings with the needle
withdrawn after use, and FIG. 4 separation of the cannula/catheter
from the needle assembly.
[0122] FIGS. 5 and 6 of the drawings show alternative positions of
the plunger 51 of the valving member 43.
[0123] In FIG. 5, the plunger 51 is in a first position with the
gasket 53 blocking fluid flow.
[0124] In FIG. 6, the plunger 51 has been manually repositioned and
the fluted portion 55 provides a passage for fluid flow.
[0125] FIG. 7 of the drawings is an assembly drawing of the device
of the present invention in a ready-to-use condition.
[0126] Aspects of the present invention have been described by way
of example only and modifications and additions thereto may be made
without departing from the spirit or scope thereof.
* * * * *